THE NORTHERN ADELAIDE PLAINS LEAKY WELLS PROJECT 1998 - 2003 DWLBC Report 2002/25 Q:\StratComs\Chloe\Admin\report_dwlbc_template.dot Page 1 of 1 The Northern Adelaide Plains Leaky Wells Project Summary 1998-2003 Tania Wilson Resource Assessment Branch Department of Water, Land and Biodiversity Conservation November 2002 Report DWLBC 2002/25 Government of South Australia Resource Assessment Branch Department of Water, Land and Biodiversity Conservation Level 11, 25 Grenfell Street, Adelaide SA 5000 GPO Box 2834, Adelaide SA 5001 Telephone National (08) 8226 0222 International +61 8 8226 0222 Fax National (08) 8463 3146 International +61 8 8463 3146 Website www.dwlbc.sa.gov.au Disclaimer Department of Water, Land and Biodiversity Conservation and its employees do not warrant or make any representation regarding the use, or results of the use, of the information contained herein as regards to its correctness, accuracy, reliability, currency or otherwise. The Department of Water, Land and Biodiversity Conservation and its employees expressly disclaims all liability or responsibility to any person using the information or advice. © Department of Water, Land and Biodiversity Conservation 2002 This work is copyright. Apart from any use as permitted under the Copyright Act 1968 (Cwlth), no part may be reproduced by any process without prior written permission from the Department of Water, Land and Biodiversity Conservation. Requests and inquiries concerning reproduction and rights should be addressed to the Director, Groundwater Resource Assessment Branch, Department of Water, Land and Biodiversity Conservation, GPO Box 2834, Adelaide SA 5001. Wilson T.C., 2002. The Northern Adelaide Plains Leaky Wells Project 1998-2003. South Australia. Department of Water, Land and Biodiversity Conservation. Report, DWLBC 2002/25. Foreword South Australia’s natural resources are fundamental to the economic and social well being of the State. One of the State’s most precious natural resources, water is a basic requirement of all living organisms and is one of the essential elements ensuring biological diversity of life at all levels. In pristine or undeveloped situations, the condition of water resources reflects the equilibrium between rainfall, vegetation and other physical parameters. Development of these resources changes the natural balance and may cause degradation. If degradation is small, and the resource retains its utility, the community may assess these changes as being acceptable. However, significant stress will impact on the ability of a resource to continue to meet the needs of users and the environment. Understanding the cause and effect relationship between the various stresses imposed on the natural resources is paramount to developing effective management strategies. Reports of investigations into the availability and quality of water supplies throughout the State aim to build upon the existing knowledge base enabling the community to make informed decisions concerning the future management of the natural resources thus ensuring conservation of biological diversity. Bryan Harris Director, Resource Assessment Branch Department of Water, Land and Biodiversity Conservation The Northern Adelaide Plains I Report DWLBC 2002/25 Leaky Wells Project Summary 1998-2003 CONTENTS FOREWORD.........................................................................................................................I CONTENTS.........................................................................................................................II 1.0 EXECUTIVE SUMMARY.............................................................................................1 2.0 INTRODUCTION..........................................................................................................5 3.0 PROJECT HISTORY...................................................................................................6 4.0 MEMORANDUM OF ADMINISTRATIVE AGREEMENT.............................................9 4.1 GENERAL...........................................................................................................9 4.2 SUMMARY OF DWLBC OBLIGATIONS............................................................9 4.3 SUMMARY OF NABCWMB OBLIGATIONS.....................................................9 4.4 SUMMARY OF PROGRESS FROM FEBRUARY 2001 TO JUNE 2002............9 4.5 PROJECT SUMMARY......................................................................................13 4.6 WELLS COMPLETED IN MULTIPLE AQUIFERS............................................20 4.7 PROPOSED WORK PROGRAM FOR 2002-2003...........................................20 5.0 SUMMARY OF EXPENDITURE................................................................................23 6.0 RECOMMENDATIONS..............................................................................................25 7.0 SI UNITS COMMONLY USED WITHIN TEXT...........................................................26 8.0 ABBREVIATIONS COMMONLY USED WITHIN TEXT.............................................26 9.0 REFERENCES ..........................................................................................................27 List of Tables Table 1. Salinity sampling breakdown of licensed wells.................................................1 Table 2. Breakdown of licensed wells providing salinity information (1998-2001).........1 Table 3. Breakdown of wells identified as potentially leaky............................................2 Table 4. Number of water samples collected from 1998-June 2002..............................2 Table 5. Breakdown of project expenditure from 1998 to June 2002.............................3 Table 6. Proposed project expenditure for 2002/03.......................................................3 Table 7. Summary of proposed work program for 2002-2003........................................4 Table 8. Results of initial investigation of 199 representative wells................................7 Table 9. Results of field investigations of well with abnormally high salinity identified from initial study................................................................................................7 The Northern Adelaide Plains II Report DWLBC 2002/25 Leaky Wells Project Summary 1998-2003 Table 10. Results for all licensed wells with available salinity data (February 2001)......10 Table 11. Results of investigations of the 80 wells with abnormally high salinity identified from available salinity data (June 2001)..........................................11 Table 12. Categories of 46 wells identified that require rehabilitation (February 2002)..12 Table 13. Current status of wells requiring rehabilitation whose owners have registered for the NHT Leaky Wells Incentive Project (September 2002)........................13 Table 14. Current status of salinity samples collected for the 1282 licensed irrigation wells (June 2002)............................................................................................13 Table 15. Breakdown of salinity samples received for each year and aquifer sampled..15 Table 16. Details of total number of wells identified as leaking for each year of the Leaky Wells Project.........................................................................................15 Table 17. Summary of Stage 1project details, current status and expected completion dates...............................................................................................................21 Table 18. Summary of Stage 2 project details, current status and expected completion dates...............................................................................................................22 Table 19. NAP Leaky Wells Project expenditure for 1999/00 financial year...................23 Table 20. NAP Leaky Wells Project expenditure for 2000/01 financial year...................23 Table 21. NAP Leaky Wells Project expenditure for 2001/02 financial year...................24 Table 22. Proposed expenditure for the Leaky Wells Project for the 2002/03 financial year.................................................................................................................25 List of Figures Figure 1. Wells requiring rehabilitation whose owners have registered with NABCWMB for the NHT Leaky Wells Incentive Project......................................................14 Figure 2. 1998-June 2002 salinity vlaues for T1 production wells compared to regional T1 salinity........................................................................................................16 Figure 3. 1998-June 2002 salinity values for T2 production wells compared to regional T2 salinity........................................................................................................17 Figure 4. 1998-June 2002 salinity values for Quaternary production wells....................18 Figure 5. Wells completed in multiple aquifers..............................................................19 List of Appendices APPENDIX A Memorandum of Administrative Agreement.............................................28 APPENDIX B Proposed Changes to the Administrative Agreement..............................38 APPENDIX C List of all licensed irrigation wells with salinity samples submitted between 1998-June 2002.........................................................................44 APPENDIX D List of 310 Licensed Irrigation Wells with no salinity sample submitted between 1998-June 2002.........................................................................64 APPENDIX E List of 14 Well Completed in Multiple Aquifers.........................................72 The Northern Adelaide Plains III Report DWLBC 2002/25 Leaky Wells Project Summary 1998-2003 1.0 EXECUTIVE SUMMARY The Resource Assessment Branch of the Department of Water Land and Biodiversity Conservation (DWLBC) is currently undertaking the ‘Northern Adelaide Plains Prescribed Wells Area Well Investigation Project’ for the Northern Adelaide and Barossa Catchment Water Management Board (NABCWMB). This report provides an overview of the issues, results to date and future directions for the project. Stage 1 of the Leaky Wells Project is designed to audit and compile an accurate list of licensed irrigation wells within the Northern Adelaide Plains (NAP) Prescribed Wells Area (PWA). Of these licensed wells pumped salinity samples were to be collected by the licence holder and submitted for analysis. From a review of these wells and recorded salinity information all wells determined to be contaminating the major production aquifers were to be identified, investigated and remedial action undertaken. Stage 2 of the Leaky Wells Project aimed to assess the condition of the 2868 abandoned and disused wells throughout the NAP. As mentioned in the Administrative Agreement, it was expected that this phase of the project would be the most intensive, requiring considerable field investigations to determine the locations and current condition of these wells. Summary of Work Completed 1998 to June 2001 It was identified that as of June 2001 there were 1499 licensed operational wells within the NAP PWA. A review of available salinity data indicated that 310 of these wells had no salinity information for the period from 1998/1999 or 1999/2000 water use year. The 2000/01 salinity sampling program resulted in 647 sample returns (Table 1) with 852 wells not sampled. Table 1. Salinity Sampling Breakdown of Licensed Wells Total Licensed Wells (June 2001) 1,499 Salinity Samples Submitted (by June 2001) 495 Bottle Returned Identifying Well Backfilled 126 Bottle returned Identifying Pump Broken 26 Total (for June 2001) 647 Wells Not Sampled (by June 2001) 852 Incorporation of the 2000/01 license holder salinity sampling into the review of recent (post 1998) salinity information identified a total of 872 wells that provide salinity data. Table 2. Breakdown of Licensed Wells Providing Salinity Information (1998 – 2001) Number of Wells with Salinity Data (1998 - 2001) 872 Salinity Data Representative of Regional Aquifer Salinity 733 Wells with High Salinity Readings – Presumed Leaking 80 Wells with Rising Salinity Trends – Listed for Future Monitoring 59 The Northern Adelaide Plains 1 Report DWLBC 2002/25 Leaky Wells Project Summary 1998-2003 Executive Summary The wells identified to have salinities greater that regional aquifer salinity were considered to be potentially leaky. Investigations of these 80 wells were undertaken (Table 3) by checking well status and undertaking geophysical logging and salinity resampling where appropriate. Table 3. Breakdown of Wells Identified as Potentially Leaky Wells Investigated as Leaky 80 Well Marked for Rehabilitation/Backfilling due to Time Since Construction 16 Wells Geophysically Logged and Shown to be Leaky 30 (of these 12 have been rehabilitated or backfilled already) Wells Not Investigated due to Stuck Pumps 7 Wells Not Investigated due to Lack of Access Permission by Well Owner 4 Wells with Pumps to be Pulled (as at June 2001) 6 Wells Where Licence Holder yet to be Contacted (as at June 2001) 5 Wells Shown Not to be Leaking 6 Wells Resampled and Shown to have Regional Aquifer Salinity Levels 6 Further information on the geophysical logging work undertaken in respect with this project can be found the in following report; “A Preliminary Report on the Geophysical Testing of Wells That Have Abnormally High Salinity, NAP Corroded Casing Survey 1999/2000”; PIRSA Report Book 2000/14. June 2001 to June 2002 Continuing work on the 80 wells mentioned previously resulted in a total of 63 licensed wells identified as a source of groundwater contamination, which would require either backfilling or rehabilitation. Owners had previously remedied 17 wells. The NABCWMB implemented the Leaky Wells Incentive Project utilising Natural Heritage Trust (NHT) funding to subsidise remediation costs incurred by owners. A total of 106 registrations of interest have been received. Completion of Stage 1 of the Leaky Wells Project has been consistently impeded by the low return of samples. As a result, DWLBC have undertaken to collect the remaining water samples to provide a complete salinity data set for the licensed wells in the NAP. Table 4 summarises the current status of the sample collection program for licensed irrigation wells. 310 samples remain and it is anticipated that these will be collected by March 2003. Table 4. Number of Water Samples Collected from 1998-June2002 Total Licensed Irrigation Wells (1998-June 2002) 1282 Salinity data representative of regional aquifer salinity 671 Wells with abnormally high salinity – presumed leaking 80 Wells with rising salinity trends – listed for future monitoring 26 Wells with salinity data requiring analysis or further sampling 195 Total Wells with Salinity Data (1998-June 2002) 972 Total Wells Not Sampled (by June 2002) 310 The Northern Adelaide Plains 2 Report DWLBC 2002/25 Leaky Wells Project Summary 1998-2003 Executive Summary Given these delays, DWLBC continued analyses of available salinity data for licensed wells and updated the list of licensed wells as identified by the project work. In addition, the collation of all available well information, well completion data and status for disused/abandoned wells commenced (Phase 1, Stage 2). Project Expenditure A summary of project expenditure from 1998 to June 2002 (Table 5) and proposed expenditure for 2002/2003 (Table 6) are provided below. Table 5. Breakdown of Project Expenditure from 1998 to June 2002 Whole of Project Expenditure DWLBC NABCWMB Project 1999/2000 Employment $53 147 $43 540 Operational Costs $15 000 $16 000 99/00 Total Project Costs $68 147 $59 540 $127 687 2000/2001 Employment $57 580 $53 390 Operational Costs $27 419 $6 610 00/01 Total Project Costs $84 999 $60 000 $144 999 2001/2002 Employment $51 474 $30 000 Operational Costs 0 0 01/02 Total Project Costs $51 474 $30 000 $81 474 Total Expenditure to 2002 (excl. GST) $204 620 $149 540 $354 160 Table 6. Proposed Project Expenditure for 2002/03 Proposed Project Expenditure (2002/03) DWLBC NABCWMB Employment FTE FTE Volmer Berens $11 214 0.2 Tania Wilson $28 035 0.5 $28 035 0.5 Scott Evans $14 662 0.2 Total Employment Costs $53 911 $28 035 Operating Costs Various $6 089 $4 965 (NEK) Total Operational Costs $6 089 $4 965 Total Project Costs (excl. GST) $60 000 $33 000 The Northern Adelaide Plains 3 Report DWLBC 2002/25 Leaky Wells Project Summary 1998-2003 Executive Summary Work Plan 2002/03 It is proposed that during the 2002/03 period the following activities will be undertaken: • Complete the investigation of licensed wells not completed during 2000/01. • Continue the identification, investigation and review of the remaining abandoned and disused wells within the NAP (Phase 1, Stage 2 of the original program). • Continuation of DWLBC sampling program of all licensed irrigation wells throughout the NAP. Table 7. Summary of proposed work program for 2002/03 Completion Date Work Outline Obtain water quality analysis for remaining 310 licensed irrigation wells, compile data and produce spatial salinity data maps March 03 Production of time series salinity information, comparison with historical data and interpretation for remaining 310 licensed irrigation wells May 03 Field verification of any wells identified with abnormally high salinity from the above analyses June 03 Half yearly Summary Report February 03 Annual Report June 03 Continuation of identification, investigation and review of approximately 3000 abandoned and disused wells throughout the NAP Ongoing The Northern Adelaide Plains 4 Report DWLBC 2002/25 Leaky Wells Project Summary 1998-2003
Description: